package com.caimiao.miao.library.bluetooth;

public class CRCUtil {

//    static {
//        System.loadLibrary("JniMiao");
//    }
//    public native char getCrcCheck(String cp, int len);

    private static final int[] crctab =
            {
                    0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011,
                    0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022,
                    0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072,
                    0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041,
                    0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2,
                    0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1,
                    0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1,
                    0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082,
                    0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192,
                    0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1,
                    0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1,
                    0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2,
                    0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151,
                    0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162,
                    0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132,
                    0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101,
                    0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312,
                    0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321,
                    0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371,
                    0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342,
                    0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1,
                    0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2,
                    0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2,
                    0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381,
                    0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291,
                    0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2,
                    0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2,
                    0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1,
                    0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252,
                    0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261,
                    0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231,
                    0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202
            };
//    unsigned short CrcCalc(const unsigned char *cp, unsigned short len)
//    {
//        unsigned short crc;
//        unsigned char comb_val;
//        crc = 0;
//        while(len--)
//        {
//            comb_val = (unsigned char)(crc >> 8) ^ *cp++;
//            crc = (unsigned short)(crc << 8) ^ crctab[comb_val];
//        }
//        return crc;
//    }

    public static int getCrcCode(byte[] cp) {
        int crc = 0x0000;
        for (int i = 0; i < cp.length; i++) {
            //   java.lang.ArrayIndexOutOfBoundsException: length=256; index=627
            crc = (crc << 8) ^ crctab[((crc >> 8) ^ cp[i]) & 0xff];
        }
        return crc;
    }

    private static long[] crc32Table = new long[256];

    static {
        long crcValue;
        for (int i = 0; i < 256; i++) {
            crcValue = i;
            for (int j = 0; j < 8; j++) {
                if ((crcValue & 1) == 1) {
                    crcValue = crcValue >> 1;
                    crcValue = 0x00000000edb88320L ^ crcValue;
                } else {
                    crcValue = crcValue >> 1;

                }
            }
            crc32Table[i] = crcValue;
        }
    }

    public static long getCrc32(byte[] bytes) {
        long resultCrcValue = 0x00000000ffffffffL;
        for (int i = 0; i < bytes.length; i++) {
            int index = (int) ((resultCrcValue ^ bytes[i]) & 0xff);
            resultCrcValue = crc32Table[index] ^ (resultCrcValue >> 8);
        }
        resultCrcValue = resultCrcValue ^ 0x00000000ffffffffL;
        return resultCrcValue;
    }

}
